About Iterative Jobs

An iterative job is a job with a control loop in which one or more processes are executed multiple times. For example, the following display shows the process flow for an iterative job. The circled numbers represent the order in which the transformations are run.

The process flow specifies that the inner Extract Balance job is executed multiple times, as specified by the Loop transformations and the CHECKLIB control table. The inner job is also called a parameterized job because it specifies its inputs and outputs as parameters. For an example of how the steps in the iterative process are performed, see Creating and Running an Iterative Job.

The job shown in the previous example uses a control table that was created in a separate library contents job. This job created a control table that contains a static list of the tables that are included in the input library at the time that the job was run. You can also reuse an existing control table or create a new one. Many times, you will want to add the library input and the Library Contents transformation directly to an iterative job, as shown in the following example.

When the input library and the Library Contents transformation are added to the iterative job, the contents of the control table are dynamically generated each time that the iterative job is run. This arrangement ensures that the list of tables in the CHECKLIB table is refreshed each time that the job is run. It also ensures that the tables are processed iteratively as each row in the control table is read.